I'm unsure there's much benefit, or at least substantial difference in feel when considering such things. Thats especially with bikes that are quite heavy in reality. A straight linear spring takes, successively, more and more weight the further you get into compression anyway. Progressive springs, unless extremely well specified, may have trouble with initial weight of bike and rider in these bikes.
Certainly don't feel from experience that its transformative on a road bike like this.
First question would be, do the current springs measure to specification ? that as a start point of considering whether to change them.
One thing to consider, before you take them apart, is the oil level that's currently in them, and if its also at correct level as this will impact their current feel in operating. With it on centre stand, take caps off fork top and "dipstick" them to see what you've got. If low, top them up to correct. You could also consider over filling by 20ml to reduce the airspace above the oil, this to help with progression as it dips into its stroke.
To basics in establishing what its like currently:- measure sag at fork stanchion with you sitting on it statically, by putting a small zip tie around the stanchion next to the seal and measuring how much its gone down in static loading. It should be about 10/20 % of travel like that. If greater to much degree, that would push you to a stronger spring rate to support static loading.
At very simple strip and clean, I'd pull the legs off stanchion, wash them out with degreasing method, clean and dry them, let ALL oil drain from damper tube etc. Refill with known level (confirmed mls volume) of Motul 5 viscosity fork oil (dedicated fork oil has better lubrication spec than alternative products) then ride it to assess what they feel like. Good oil, in good condition and at correct level, will likely make a fork set feel much better in use if coming from an uncertain current setup.
